Funds are requested to determine the feasibility of using voltage sensitive dyes for studies seeking to determine the functional organization of macaque striate cortex. If this approach can be made to work it will have the advantage over previous techniques, such as 2-deoxy Glucose, of allowing successive determinations of cortical activity patterns that develop in response to sucessively presented visual stimuli - all in the same part of striate cortex from one animal. In addition, the temporal resolution of currently available voltage sensitive dyes is such that the real-time, dynamic following of cortical activity patterns, may also be possible.